PROJECT SUMMARY Light is a profoundly important regulator of physiology and behavior across a wide range of organisms. Despite its importance for influencing physiology and behavior, the circuits by which light information is relayed from the eye to the brain to influence behavior are not well understood. The central goal of this proposal is to genetically map the circuits underlying vision by focusing on the connectivity and influence of the relay neurons of the retina, the retinal ganglion cells. We will use mouse genetics to identify the influence of specific retinal ganglion cell subtypes on behavior, investigate the influence of these retinal ganglion cells on signaling within visual nuclei, and map the connectivity of retinal ganglion cells in the brain at the cellular level. These studies will enhance our understanding of visual processing and have the potential to better inform our understanding and treatment of dysfunction and injury of the visual system to better improve human health.